All Crysis titles went on sale on this website, i trust it personally, its my second favorite site besides steam to purchase my games. They are having a sale today on Crysis titles enjoy while you can.

Now's the time to buy Crysis 1 for only $10!!!

http://www.gamersgate.com/offers

G2play sells Crysis 2 for $18.49 and it's not discounted

Soon they will start giving it for free with other games.